A top alien-hunting boffin has said that current efforts seeking extraterrestrial intelligent life are unlikely ever to work - not because there couldn't be any aliens out there, but because the methods themselves are wrong. He proposes several radical new means of finding out whether we really are alone in the universe.
Professor Paul Davies, physicist and cosmologist, is a Brit by origin but these days is chief of the "Beyond: Center for Fundamental Concepts in Science" outfit at Arizona State uni. He explains his thinking on the need to revamp alien-seeking methods in an article published yesterday by Blighty's Institute of Physics.
The main method used by humanity today to search for intelligent life elsewhere is the use of radio telescopes to scan the skies for RF-type signals, mainly as part of the American Search for Extra Terrestrial Intelligence (SETI) project.
In fifty years of looking, SETI has yielded very little of interest - though it did pick up a mysterious 72-second pulse, the so-called "Wow!"* signal, back in 1977. This has never been satisfactorily explained and has never recurred - on its own it doesn't really seem to mean anything.
According to Davies, the slender results delivered by SETI are very much to be expected. Even with the new Allen Telescope Array, gifted to the project by famed submarine-fancying billionaire Microsoft founder Paul Allen**, the prof doesn't expect radio sky-scan to produce anything much, even if the universe is crawling with aliens.
This is because radio signals which can be detected across interstellar distances aren't trivial to generate, and would mostly be directional. The old and excellent science fiction gag of TV broadcasts being picked up and avidly watched by aliens isn't realistic, fun though it is as a concept: the only real means open to humanity at present for sending interstellar messages is the use of powerful radar telescopes such as the famous Arecibo facility. (Or the Ukrainian job lately rented by Bebo in order to beam a blast of mindless web-2.0 babble at the possible hapless residents of the Gliese 581 system.)
Thus detectable radio signals would probably have to be purposeful interstellar signals, not merely incidental emissions naturally given off by any sufficiently advanced civilisation. According to Davies:
Unless the galaxy is teeming with civilizations frenetically swapping radio messages, it is exceedingly improbable that we would stumble upon a signal directed at another planet that simply passed our way by chance. A more realistic hope is that an alien civilization has built a powerful beacon to sweep the plane of the galaxy like a lighthouse. A beacon could serve a variety of purposes: as a monument to a long-vanished culture; as a way to attract attention and make first contact; as an artistic, cultural or religious symbol; or the cosmic equivalent of graffiti. It might even be a cry for help, or, as with the humble lighthouse, a warning.